In environments such as courtrooms, one advocate, then another, then a witness, then the judge may all speak, from different locations in the room, one after the other. The speeches are often accompanied by a high degree of paper rustle as files are referred to, and by other noise generated from the people in the courtroom. External low frequency noise caused by traffic or aircraft overflight may also be present.
The sound amplification and recording system in such an environment will typically comprise a series of microphones placed at different locations around the room. All the microphones are connected via a switching station to mixers, amplifiers, and loudspeaking and recording equipment. Typically the switching station is controlled by an operator who observes the activity in the courtroom and switches the microphones on and off as appropriate. The performance of such a system is highly dependent on the operator's skill, and requires the concentrated attention of the operator for long periods of time if high quality is to be sustained.